Drive unit integrated rotating electrical machine

ABSTRACT

To obtain a drive unit integrated rotating electrical machine that makes it easier to connect power circuits and achieves not only excellent vibration resistance but also excellent heat releasing properties. 
     Means for Solution 
     A drive unit integrated rotating electrical machine has a motor, a drive unit driving the motor under control and provided with power switching elements and conductors passing a current to the power switching elements, and a heat sink cooling the drive unit, which are combined into one unit. The drive unit integrated rotating electrical machine is characterized in that: the power switching elements are molded and formed into mold modules in a state in which terminals thereof are exposed; the conductors are insert-molded in a frame in a state in which terminals thereof are exposed; and the exposed terminals of the mold modules are connected to the exposed terminals of the insert-molded conductors and the mold modules are firmly fixed to the heat sink.

TECHNICAL FIELD

The present invention relates to a drive unit integrated rotatingelectrical machine employed in an electric power steering device or thelike.

BACKGROUND ART

A drive unit integrated rotating electrical machine in the related artemployed in an electric power steering device or the like uses a ceramicboard as a drive board in a drive unit part (see, for example, PTL 1).Further, drive semiconductor switching elements (for example, MOS-FETs)are mounted by bare chip mounting on the ceramic board, which is thedrive board (see, for example, PTL 1 and PTL 2).

CITATION LIST Patent Literature

PTL 1: JP-A-2010-12819 (page 1 and FIG. 2)

SUMMARY OF INVENTION Technical Problem

The drive unit integrated rotating electrical machine in the related artdescribed in PTL 1 uses a ceramic board as the drive board and drivesemiconductor switching elements are generally mounted on the ceramicboard by bare chip mounting.

The drive unit integrated rotating electrical machine is formed asfollows. That is, the semiconductor switching elements are mounted on aceramic board and this ceramic board is installed to a heat sink, forexample, by soldering. Then, after a frame assembly (assembled body)(hereinafter, referred to as the frame ASSY), which is provided withterminals to feed power to the semiconductor switching elements and acontrol terminal portion of the semiconductor switching elements, isattached to the heat sink, the semiconductor switching elements areconnected to the frame ASSY one by one using, for example, aluminumwires.

Hence, there is a problem that productivity is poor.

Further, the ceramic board is fixed to the heat sink, for example, bysoldering, and cracking occurs in the solder over temperature cycles inuse. Hence, there is a problem that thermal resistance between theceramic substrate and the heat sink becomes larger.

Furthermore, there is a problem that the ceramic board comes off fromthe heat sink because of environmentally-induced vibrations.

The present invention solves the problems as above and has an object toobtain a drive unit integrated rotating electrical machine that makes iteasier to connect drive semiconductor switching elements and a frameASSY provided with power feeding terminals and also achieves excellentvibration resistance.

Solution to Problem

A drive unit integrated rotating electrical machine according to theinvention omits a drive board and instead has a rotating electricalmachine, a drive unit driving the rotating electrical machine undercontrol and provided with power switching elements and conductorspassing a current to the power switching elements, and a heat sinkcooling the drive unit, which are combined into one unit. The powerswitching elements are molded and formed into mold modules withterminals thereof being exposed. The conductors are insert-molded in aframe with terminals thereof being exposed. The exposed terminals of themold modules are connected to the exposed terminals of the insert-moldedconductors and the mold modules are firmly fixed to the heat sink.

Advantageous Effects of Invention

According to the invention, it becomes possible to obtain a drive unitintegrated rotating electrical machine that makes it easier to connectmold modules in which power switching elements are molded with theterminals thereof being exposed and respective terminals of a frame inwhich conductors passing a current to the power switching elements areinsert-molded and also enhances vibration resistance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross section including a speed reducer and showing a driveunit integrated rotating electrical machine according to a firstembodiment of the invention.

FIG. 2 is an axial cross section showing the drive unit integratedrotating electrical machine according to the first embodiment of theinvention.

FIG. 3 is a top view omitting a housing and a control board of a driveunit part and showing the drive unit integrated rotating electricalmachine according to the first embodiment of the invention.

FIG. 4 is a partial cross section of a heat sink, a mold module, and aframe ASSY on section A-A of FIG. 3 to show the drive unit integratedrotating electrical machine according to the first embodiment of theinvention.

FIG. 5 is a partial cross section of a heat sink, a mold module, and aframe ASSY on section A-A of FIG. 3 to show a drive unit integratedrotating electrical machine according to a second embodiment of theinvention.

FIG. 6 is a perspective view of a mold module back surface to show thedrive unit integrated rotating electrical machine according to thesecond embodiment of the invention.

FIG. 7 is a partial cross section of a heat sink, a mold module, and aframe ASSY on section A-A of FIG. 3 to show a drive unit integratedrotating electrical machine according to a third embodiment of theinvention.

FIG. 8 is a side view showing a drive unit integrated rotatingelectrical machine according to a fourth embodiment of the invention.

FIG. 9 is a partial cross section of a heat sink, a mold module, and aframe ASSY on section A-A of FIG. 3 to show a drive unit integratedrotating electrical machine according to a fifth embodiment of theinvention.

FIG. 10 is a circuit diagram of the drive unit integrated rotatingelectrical machine according to the first embodiment of the invention.

FIG. 11 is a developed view omitting a housing and a control board of adrive unit part and showing the drive unit integrated rotatingelectrical machine according to the first embodiment of the invention.

FIG. 12 is a perspective view omitting a housing and a control board ofa drive unit part and showing the drive unit integrated rotatingelectrical machine according to the first embodiment of the invention.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a first embodiment of the invention will be described usingFIG. 1 to FIG. 3 and FIG. 10 to FIG. 12. FIG. 1 is a cross sectionshowing a drive unit integrated rotating electrical machine according tothe first embodiment of the invention and a speed reducer. FIG. 2 is anaxial cross section showing the drive unit integrated rotatingelectrical machine of the invention. FIG. 3 is a cross section of adrive unit part showing the drive unit integrated rotating electricalmachine of the invention. FIG. 4 is a partial cross section of a heatsink, a mold module, and a frame ASSY on section A-A of FIG. 3 to showthe drive unit integrated rotating electrical machine of the invention.A drive unit 8 uses a mold module for a power switching element FETps, amotor relay FETry, and a power-supply relay RyM in each phase, that is,a phase U, a phase V, and a phase W. FIG. 4 shows a cross section of thephase V as a representative and omits cross sections of the otherphases. It should be appreciated, however, that the other phases are ofthe same configuration as the phase V.

Referring to FIG. 1 to FIG. 4, a rotating electrical machine 2 is apermanent magnet synchronous motor and a three-phase stator winding 5 iswound around a stator core 3 formed of a lamination of magnetic steelsheets via a resin insulator 4. Wirings of the respective phases arewye- or delta connected by a winding terminal 7 stored in a resinterminal holder 6.

A motor terminal 9 to establish an electrical connection with the driveunit 8 is attached to the winding terminal 7.

The stator core 3 is press-fit in an iron frame 10 and forms a stator 11of the motor.

There is a bottom portion at one end of the frame 10 and a rear bearingbox portion 14 in which to store a rear bearing 13 supporting one end ofa rotor 12 is formed at a center of the bottom portion.

A magnet 16 generating a magnetic field is attached along an outerperipheral portion of a shaft 15 of the rotor 12.

The other end of the frame 10 is open and provided with a mating portion18 to couple the frame 10 to a housing 17 of the drive unit 8.

The housing 17 is formed of a die cast molded article made of aluminumalloy and joined to a heat sink 19 of the drive unit 8 at one end.

The heat sink 19 is formed of a die cast molded article made of aluminumalloy. A front bearing box portion 21 in which to store a front bearing20 supporting one end of the rotor is formed at a center of the heatsink.

The housing 17 and the heat sink 19 together form a drive unit storingportion 22.

An attachment mating portion 24 to attach the heat sink 19 to a speedreducer 23 is provided at the other end of the heat sink 19.

A resolver, which is a rotation sensor 25, is attached to the heat sink19 at the center on the front side.

A boss 26, which is a coupling to couple the shaft 15 to the speedreducer 23, is attached to the shaft 15 at an end on the front side.

The drive unit 8 has a control board 29 made of glass epoxy on which amicro-computer 27 and an FET drive circuit 28 are mounted and moldmodules (semiconductor packages) 30 molded from resin and on which powerelements (semiconductor switching elements), such as power MOSFETs, aremounted. A frame ASSY 40 is provided between the control board 29 andthe mold modules 30. Battery potential copper terminals B (hereinafter,referred to as the terminals B) 41 to supply power to the mold modules30 and ground potential terminals G (hereinafter, referred to as theterminal G) 42 are insert-molded with resin and formed integrally withthe frame ASSY 40. The frame ASSY 40 is fixed to the heat sink 19 withframe ASSY fixing screws 48.

Each mold module 30 is pressed parallel to and against an mold moduleattachment surface of the heat sink 19 uniformly across the entiresurface as the center portion of the mold module 30 is pressed by anelastic material 46 attached to the frame ASSY 40 and is thereforeattached in close contact with an inner wall of the heat sink 19 viaresin 35. Hence, it is configured in such a manner that heat generatedin the power elements in the mold modules 30 is transferred to the heatsink 19.

Also, the mold module 30 is provided with a terminal (hereinafter,referred to as the terminal MB) 31 of battery potential in the moldmodule 30 to feed power to the internal power MOSFET, a terminal(hereinafter, referred to as the terminal MG) 32 of ground potential inthe mold module 30, mold module signal terminals 34 to control the powerMOSFET, and a mold module motor terminal 33 to feed power from the moldmodule 30 to the motor.

The mold module signal terminals 34 are connected to the control board29 and the mold module motor terminal 33 is connected to the motorterminal 9.

After the mold modules 30 are installed to the heat sink 19 using theframe ASSY 40, the terminals MB 31 and the terminals MG 32 are joined,respectively, to the terminals B 41 and the terminals G 42 of the frameASSY 40, respectively, by welds 71 and 72.

The heat sink 19 stores therein a capacitor 45 absorbing ripples of acurrent flown to the rotating electrical machine 2 and is connected tothe mold modules 30 via the terminals B 41 and the terminals G 42 of theframe ASSY 40. The heat sink 19 also stores an unillustrated coilabsorbing noises and is connected to a connector portion 50 via theterminals B 41 of the frame ASSY 40.

The housing 17 is provided with a housing radially protruding portion51. A housing axially opening portion 52, which is a connectorattachment portion, is provided at an axial end of the housing radiallyprotruding portion 51. The connector portion 50 is attached to thehousing axially opening portion 52 and the connector portion 50 isprovided with a power-supply connector 53 and a signal connector 54.

The heat sink 19 is provided with a heat sink radially protrudingportion 55 at an opposing position to the housing radially protrudingportion 51 and with a heat sink opening portion 60 at an axial end ofthe heat sink radially protruding portion 55.

Power-supply terminals 43 and signal terminals 44 extending from theframe ASSY 40 protrude axially from the heat sink opening portion 60.

The power-supply terminals 43 and the signal terminals 44 are connectedto the respective corresponding terminals, that is, the power-supplyconnector terminal 53 and the signal connector terminal 54 extendingfrom the connector portion 50 to the housing axially opening portion 52,by welding or the like at positions at which the power-supply terminals43 and the signal terminals 44 protrude axially from the heat sinkopening portion 60.

A cover 65 is provided to the heat sink opening portion 60. The cover 65covers a connector connection portion 66 including connection portionsbetween the power-supply terminals 43 and the power-supply connectorterminals 63 and connection portions between the signal terminals 44 andsignal connector terminals 64. Airtight and waterproof sealing by sealresin is applied to a contact surface of the cover 65 and the heat sink19 when a need arises.

In FIG. 10, alpha-numeral 8CB denotes a power-supply connector portionwhich connects the drive circuit 8 and a battery B and is provided tothe drive circuit 8.

In the drive-unit integrated rotating electrical machine configured inthis manner, the mold modules 30 are pressed at the center portions ofthe mold modules 33 by the elastic materials 46 attached to the frameASSY 40, so that the terminals MB 31 and the terminals MG 32 are joined,respectively, to the terminals B 41 and the terminals G 42 of the frameASSY 40, respectively, by the welds 71 and 72 in a state in which themold modules 30 are pressed uniformly, parallel to and against theattachment surface of heat sink. Further, because the mold modules 30are firmly fixed to the heat sink 19 with the resin 35, heat generatedin the mold modules 30 can be transferred to the heat sink 19homogeneously and more excellent vibration resistance can be achieved.Furthermore, because connection by welding is easier than by wirebonding in the related art, excellent productivity can be achieved.

In addition, the drive unit integrated rotating electrical machineincludes the drive unit 8 formed of the heat sink 19 on which the powercircuits are mounted and the housing 17 containing internal components,and the rotating electrical machine 2 formed of the stator 11 and therotor 12, which are combined into one unit sequentially from theattachment side of the speed reducer 23 substantially coaxially with therotation shaft of the rotor 12. Hereinafter, a rotating electricalmachine configured in this manner is referred to as the drive unitintegrated rotating electrical machine. According to this configuration,the mold modules 30 receive vibrations from the rotating electricalmachine in the coaxial integral structure. However, the mold modules 30are pressed against the heat sink 19 by the frame ASSY 40, and the heatsink 19 is attached to the speed reducer 23, which is a fixed point.Hence, the mold modules 30 are advantageous in vibration resistance. Inaddition, because the heat sink 19 on which are mounted the mold modules30 is attached to the speed reducer 23, heat generated in the moldmodules 30 is readily transferred to the speed reducer 23. Hence,excellent heat releasing properties can be achieved.

Second Embodiment

A second embodiment of the invention will now be described using FIG. 5.FIG. 5 is a partial cross section of the heat sink 19, the mold module30, and the frame ASSY 40 on the section A-A of FIG. 3 to show a driveunit coaxially integrated rotating electrical machine according to thesecond embodiment of the invention. The drive unit 8 uses a mold modulefor a power switching element FETps, a motor relay FETry, and apower-supply relay RyM in each phase, that is, a phase U, a phase V, anda phase W. FIG. 5 shows a cross section of the phase V as arepresentative and omits cross sections of the other phases. It shouldbe appreciated, however, that the other phases are of the sameconfiguration as the phase V. FIG. 6 is a perspective view of the moldmodule 30 of FIG. 5 showing a surface mounted onto the heat sink 19. Incomparison with the counterpart of the first embodiment above, the driveunit coaxially integrated rotating electrical machine of the secondembodiment is different in the configuration of a part described in thefollowing.

Mold module back surface protruding portions 36 are provided to theattachment surface to the heat sink 19 of each mold module 30 mounted onthe top surface of the heat sink 19. The terminal MB 31, the terminal MG32, and the mold module motor terminal 33 of the mold module are exposedto the attachment surface to the heat sink 19 of the mold module 30.

Also, frame ASSY protruding portions 47 of substantially a sphericalshape are provided to the frame ASSY 40. The frame ASSY 40 is attachedto the heat sink 19 in a state in which the frame ASSY protrudingportions 47 are in contact with the mold modules 30.

In a state in which the frame ASSY protruding portions 47 of the frameASSY 40 are in contact with the mold modules 30, the frame ASSY 40 andthe heat sink 19 have a clearance in between. When the frame ASSY 40 isfixed to the heat sink 19 with the frame ASSY fixing screws 48, theframe ASSY 40 undergoes deflection and the frame ASSY 40 and the heatsink 19 come into contact with each other. In this instance, the moldmodules 30 are pressed against the heat sink 19 by the frame ASSYprotruding portions 47 of the frame ASSY 40.

Resin 35 is present between the mold modules 30 and the heat sink 19 soas to transfer heat of the mold modules 30 to the heat sink 19. Theresin 35 is hardening resin.

Also, an insulating layer is provided to the heat sink 19 on the surfaceon which the mold modules 30 are mounted.

Also, the resin 35 is applied in an amount large enough to overflow tothe outer peripheral portion of the mold module 30 from the surfaceabutted on the heat sink 19.

In the drive unit coaxially integrated rotating electrical machineconfigured in this manner, the mold modules 30 are fixed to the heatsink 19 with the resin 35 by providing the mold module back surfaceprotruding portions 36 so as to produce a clearance of a uniformthickness between the mold modules 30 and the heat sink 19. It thusbecomes possible to release heat generated in a plurality of switchingelements in each mold module 30 to the heat sink 19 homogeneously.

In a case where the clearance has a non-uniform thickness, heat isreleased inhomogeneously from a plurality of the switching elements inthe mold module 30 and temperatures of the switching elements becomeequal. In order to prevent overheating of the mold module 30, heatgeneration of the switching elements is lowered by suppressing a currentflowing through the switching elements when any one of the switchingelements reaches a maximum temperature so as to protect the switchingelement reaching the maximum temperature from breaking. Hence, a currentis suppressed even when the other switching elements have a margin oftemperature from the maximum temperature.

When the clearance is made uniform, variances in temperature among therespective switching elements can be lessened by making thermalresistances from the respective switching elements to the heat sink 19equal. It thus becomes possible to enhance an output and extend anoperating time of the drive unit coaxially integrated rotatingelectrical machine.

Further, because temperatures of the respective switching elements canbe equal, it becomes possible to enhance reliability of the switchingelements.

Further, the attachment surface to the heat sink 19 of the mold module30 is provided with the protrusions of a uniform height made of resinfrom which the mold module is molded. Hence, a clearance can be securedbetween the mold module and the heat sink. Also, because it is no longernecessary to control the clearance to be uniform at the end of thefacility, the machinability can be enhanced.

Also, the mold modules 30 are attached to the heat sink 19 assubstantially the center portions of the mold modules 30 are pressed bypoint contact using the protrusions of substantially a spherical shapeprovided to the frame ASSY 40. It thus becomes possible to press themold modules 30 against the heat sink 19 via the protrusions of the moldmodules 30 in such a manner that a clearance between the heat sink 19and the mold modules 30 becomes uniform while preventing the moldmodules 30 from tilting with respect to the attachment surface of theheat sink 19. In comparison with a case where the elastic members areprovided between the mold modules 30 and the frame ASSY 40, the elasticmembers can be omitted and the machinability can be enhanced. Inaddition, because the mold modules 30 are pressed by the frame ASSY 40,vibration resistance can be enhanced further.

The respective electrodes of the terminal MB 31, the terminal MG 32, andthe mold module motor terminal 33 of the mold module 30 are exposed tothe heat sink attachment surface of the mold module 30 and are thereforein direct contact with the resin 35. It thus becomes possible to lowerthermal resistances between the respective switching elements and theheat sink 19. This capability is advantageous in heat releasingproperties.

Also, the resin 35 between the mold modules 30 and the heat sink 19 ishardening resin herein. In a case where conductive foreign matter ismixed with the resin, a product becomes defective when a short circuitoccurs between the electrode from which the foreign matter is exposedand the heat sink 19. However, by checking the occurrence of a shortcircuit after the resin is hardened, defective products can be removedduring the fabrication process. Also, because an adhesive is hardenedand the foreign matter is fixed therein, should the foreign matter bemixed with the resin, a short circuit does not occur once the productsare determined as being non-defective products by a check after theresin is hardened. Hence, reliability can be enhanced.

In addition, because the mold modules 30 are fixed to the heat sink 19more firmly by the hardening of the resin, vibration resistance can beenhanced, too.

Further, the insulating layer (for example, alumite) is provided to theheat sink 19 on the surface on which the mold modules 30 are mounted.Owing to this configuration, should the mixing of air bubbles give riseto a void in a layer of the resin 35 between the mold modules 30 and theheat sink 19, the presence of the insulating layer can ensure electricalinsulation between the mold modules 30 and the heat sink 19. Hence,reliability can be enhanced further.

Further, the resin 35 is applied in an amount large enough to overflowfrom the outer periphery of the attachment surface to the heat sink 19of the mold module 30. Accordingly, the resin 35 can be applied to theentire attachment surface to the heat sink 19 of the mold module 30 in areliable manner. In addition, because the resin 35 overflows from theouter peripheral portion of the mold module 30, it becomes possible toconfirm that the resin is applied to the entire surface in a reliablemanner. The products can be therefore manufactured in a stable manner.

Third Embodiment

A third embodiment of the invention will now be described using FIG. 7.FIG. 7 is a partial cross section of the heat sink, the mold module, andthe frame ASSY on the section A-A of FIG. 3 and shows a drive unitcoaxially integrated rotating electrical machine according to the thirdembodiment of the invention. The drive unit 8 uses a mold module for apower switching element FETps, a motor relay FETry, and a power supplyrelay RyM in each phase, that is, a phase U, a phase V, and a phase W.FIG. 7 shows a cross section of the phase V as a representative andomits cross sections of the other phases. It should be appreciated,however, that the other phases are of the same configuration as thephase V. In comparison with the counterparts of the first and secondembodiments above, the drive unit coaxially integrated rotatingelectrical machine of the third embodiment is different in theconfiguration of a part described in the following.

In the third embodiment, mold module back surface protruding portionslike those in the second embodiment above are not provided to theattachment surface to the heat sink 19 of the mold module 30 and theresin 35 between the mold module 30 and the heat sink 19 include fillers37 therein.

The fillers 37 are furnished with a function of enhancing heat transfer.In addition, owing to the fillers 37, the clearance between the moldmodules 30 and the heat sink 19 can be provided as a uniform clearanceaccording to sizes of the fillers 37.

The fillers 37 include the ones of a small size and the ones of a largesize and the fillers of the maximum size are distributed homogeneouslywithin in the resin 35. The clearance can be provided substantiallyuniformly by the fillers 37. It thus becomes possible to release heatgenerated in a plurality of the switching elements in the mold module 30to the heat sink 19 homogeneously.

Also, variances in temperature among the respective switching elementscan be lessened by making thermal resistances from the respectiveswitching elements to the heat sink 19 equal. It thus becomes possibleto enhance an output and extend an operating time of the drive unitcoaxially integrated rotating electrical machine.

The other advantages are the same as those of the second embodimentabove.

Fourth Embodiment

A fourth embodiment of the invention will now be described using FIG. 8.FIG. 8 is a side view showing a drive unit coaxially integrated rotatingelectrical machine according to the fourth embodiment of the invention.In comparison with the counterparts of the first to third embodimentsabove, the drive unit coaxially integrated rotating electrical machineof the fourth embodiment is different in configuration in a partdescribed in the following.

In the fourth embodiment, the drive unit coaxially integrated rotatingelectrical machine is formed to have a coaxial integral structure havinga motor part and a drive unit part combined sequentially in this orderfrom the side of the speed reducer 23.

In the drive unit coaxially integrated rotating electrical machineconfigured in this manner, the mold modules 30 are attached at positionsfarther from the attachment portion of the speed reducer 23 in thecoaxial integral structure. This configuration is disadvantageous interms of vibrations. However, the mold modules 30 are attached to theheat sink 19 with resin and, moreover, pressed by the frame ASSY 40.Hence, excellent vibration resistance can be achieved.

Fifth Embodiment

A fifth embodiment of the invention will now be described using FIG. 9.FIG. 9 is a partial cross section of the heat sink, the mold module, andthe frame ASSY on the section A-A of FIG. 3 and shows a drive unitcoaxially integrated rotating electrical machine according to the fifthembodiment of the invention. The drive unit 8 uses a mold module for apower switching element FETps, a motor relay FETry, and a power supplyrelay RyM in each phase, that is, a phase U, a phase V, and a phase W.FIG. 9 shows a cross section of the phase V as a representative andomits cross sections of the other phases. It should be appreciated,however, that the other phases are of the same configuration as thephase V. In comparison with the counterparts of the first to thirdembodiments above, the drive unit coaxially integrated rotatingelectrical machine of the fifth embodiment is different in theconfiguration of a part described in the following.

In the fifth embodiment, mold module back surface protruding portionslike those in the second embodiment above are not provided to theattachment surface to the heat sink 19 of the mold module 30 and aninsulating plate 38 (for example, a ceramic plate) of a uniformthickness is provided between the mold modules 30 and the heat sink 19.

The terminal MB 31, the terminal MG 32, and the mold module motorterminal 33 of the mold module 30 are exposed to the attachment surfaceto the heat sink 19 of the mold module 30.

Heat conductive grease 39 is interposed between the mold module 30 andthe insulating plate 38 and between the insulating plate 38 and the heatsink 19.

Owing to the insulating plate 38 of a uniform thickness, heat generatedin a plurality of switching elements in the mold module 30 can bereleased homogeneously to the heat sink 19.

Also, variances in temperature among the respective switching elementscan be lessened by making thermal resistances from the respectiveswitching elements, which are power elements, such as FETs, to the heatsink 19 equal. It thus becomes possible to enhance an output and extendan operating time of the drive unit coaxially integrated rotatingelectrical machine.

Further, because the mold modules 30 and the heat sink 19 can beelectrically isolated in a reliable manner by the insulating plate 38,insulation properties can be enhanced.

The above has described that the heat conductive grease 39 is providedto the both surfaces of the insulating plate. It should be appreciated,however, that resin is used instead.

The mold modules of the first to fifth embodiments have been describedas the mold modules 30, each of which includes the power switchingelement FETps and the motor relay FETry to feed power to the motor inthe form of a mold module. It should be appreciated, however, that thethe mold modules are not limited to the mold modules 30. Advantages sameas those described above can be obtained even in a case where the moldmodule is a mold module which includes the power-supply relay RyM thatinterrupts power feeding to the mold module at the occurrence of afailure or during a non-operating time in the form of a mold module.

The first to fifth embodiments above have described a coaxiallyintegrated rotating electrical machine. However, the same can be said ina case where the drive unit is provided separately or attached to theside surface of the rotating electrical machine.

According to the first to fifth embodiments above, a plurality of moldmodules are used in the coaxially integrated rotating electricalmachine. In a case where the mold modules are arranged concentricallywith the motor rotation shaft, the respective mold modules can bepressed more uniformly by the frame ASSY. Hence, this configuration ismore advantageous in terms of vibration resistance.

In FIG. 1 to FIG. 6, the same reference numerals denote the same orequivalent portions.

As can be obvious from the description above and the drawings describedabove, FIG. 1 to FIG. 12 and the first to fifth embodiments havetechnical characteristics as follows.

Characteristic 1

A drive unit integrated rotating electrical machine includes a motor anda drive unit driving the motor under control and having a case structureformed of a metal heat sink and a housing, which are combined into oneunit. The drive unit integrated rotating electrical machine ischaracterized as follows. That is, the drive unit of the drive unitintegrated rotating electrical machine has power circuit components, andthe power circuit components are a plurality of power switching elementsFETps forming abridge circuit and motor relay switching elements FETryperforming ON and OFF control of motor currents supplied to the motorfrom the respective power switching elements. The power circuitcomponents are mounted on terminals, which are conductive members. Thepower circuit components and the terminals are molded into one unit withmold resin. The resulting mold modules have the terminals partiallyexposed to the outside of the mold resin for the purpose of connection.The mold modules are disposed between a frame ASSY in which power-supplyterminals are insert-molded and the heat sink. In the drive unitconfigured in this manner, the mold modules are connected and coupled tothe connection terminals of the frame ASSY and disposed on the heatsink.

Characteristic 2

The drive unit integrated rotating electrical machine described inCharacteristic 1 is characterized in that the mold modules are firmlyfixed to the heat sink with resin.

Characteristic 3

The drive unit integrated rotating electrical machine described inCharacteristic 2 is characterized in that the mold modules and the heatsink have a clearance in between.

Characteristic 4

The drive unit integrated rotating electrical machine described inCharacteristic 3 is characterized in that the mold modules are pressedby the frame.

Characteristic 5

The drive unit integrated rotating electrical machine described inCharacteristic 4 is characterized in that protruding portions areprovided by molding to heat sink attachment surfaces of the moldmodules.

Characteristic 6

The drive unit integrated rotating electrical machine described inCharacteristic 4 is characterized in that the resin includes fillerstherein.

Characteristic 7

The drive unit integrated rotating electrical machine described in anyone of Characteristics 4 to 6 is characterized in that elastic membersare provided between the mold modules and the frame ASSY.

Characteristic 8

The drive unit integrated rotating electrical machine described in anyone of Characteristics 4 to 6 is characterized in that protrudingportions are provided to mold module pressing portions of the frameASSY.

Characteristic 9

The drive unit integrated rotating electrical machine described in anyone of Characteristics 3 to 8 is characterized in that electrodes areexposed on a side of a heat sink attachment surfaces of the moldmodules.

Characteristic 10

The drive unit integrated rotating electrical machine described inCharacteristic 9 is characterized in that the resin is hardening resin.

Characteristic 11

The drive unit integrated rotating electrical machine described inCharacteristic 9 is characterized in that an insulating layer isprovided to a mold module attachment surface of the heat sink.

Characteristic 12

The drive unit integrated rotating electrical machine described inCharacteristic 1 is characterized in that an insulating plate isprovided between the mold modules and the heat sink.

Characteristic 13

The drive unit integrated rotating electrical machine described in anyone of Characteristics 2 to 4, 9, and 10 is characterized in that theresin is applied in an amount large enough to overflow from outerperipheries of the mold modules.

Characteristic 14

The drive unit integrated rotating electrical machine described in anyone of Characteristics 1 to 13 is characterized in that a motor part anda drive unit part are combined sequentially from a speed reducerattachment side so as to form a coaxial integral structure.

Characteristic 15

The drive unit integrated rotating electrical machine described in anyone of Characteristics 1 to 13 is characterized in that a drive unitpart and a motor part are combined sequentially from a speed reducerattachment side so as to form a coaxial integral structure.

1.-15. (canceled)
 16. A drive unit integrated rotating electricalmachine including a motor, a drive unit driving the motor under controland provided with power switching elements, and a heat sink cooling thedrive unit, which are combined into one unit, the drive unit integratedrotating electrical machine being characterized in that: the powerswitching elements are molded and formed into mold modules in a state inwhich terminals thereof are exposed; the mold modules are firmly fixedto the heat sink; conductors passing a current to the power switchingelements are insert-molded in a frame in a state in which terminalsthereof are exposed; and the exposed terminals of the power switchingelements are connected to the exposed terminals of the conductors. 17.The drive unit integrated rotating electrical machine according to claim16, characterized in that: the mold modules are firmly fixed to the heatsink with resin.
 18. The drive unit integrated rotating electricalmachine according to claim 17, characterized in that: a clearance isformed between the mold modules and the heat sink and the resin ispresent in the clearance.
 19. The drive unit integrated rotatingelectrical machine according to claim 18, characterized in that: themold modules are pressed against the heat sink by the frame.
 20. Thedrive unit integrated rotating electrical machine according to claim 19,characterized in that: protruding portions that form the clearance areprovided to heat sink attachment surfaces of the mold modules.
 21. Thedrive unit integrated rotating electrical machine according to claim 17,characterized in that: the resin includes fillers therein.
 22. The driveunit integrated rotating electrical machine according to claim 19,characterized in that: the resin includes fillers therein.
 23. The driveunit integrated rotating electrical machine according to claim 18,characterized in that: elastic members elastically pressing the moldmodules against the heat sink are provided between the mold modules andthe frame.
 24. The drive unit integrated rotating electrical machineaccording to claim 22, characterized in that: elastic memberselastically pressing the mold modules against the heat sink are providedbetween the mold modules and the frame.
 25. The drive unit integratedrotating electrical machine according to claim 18, characterized inthat: protruding portions pressing the mold modules on the frame againstthe heat sink are provided.
 26. The drive unit integrated rotatingelectrical machine according to claim 22, characterized in that:protruding portions pressing the mold modules on the frame against theheat sink are provided.
 27. The drive unit integrated rotatingelectrical machine according to claim 18, characterized in that:electrodes of the mold modules are exposed on a side of a heat sinkattachment surface.
 28. The drive unit integrated rotating electricalmachine according to claim 26, characterized in that: electrodes of themold modules are exposed on a side of a heat sink attachment surface.29. The drive unit integrated rotating electrical machine according toclaim 18, characterized in that: the resin is hardening resin.
 30. Thedrive unit integrated rotating electrical machine according to claim 28,characterized in that: the resin is hardening resin.
 31. The drive unitintegrated rotating electrical machine according to claim 18,characterized in that: an insulating layer is provided to a mold moduleattachment surface of the heat sink.
 32. The drive unit integratedrotating electrical machine according to claim 26, characterized inthat: an insulating layer is provided to a mold module attachmentsurface of the heat sink.
 33. The drive unit integrated rotatingelectrical machine according to claim 16, characterized in that: aninsulating plate is provided between the mold modules and the heat sink.34. The drive unit integrated rotating electrical machine according toclaim 17, characterized in that: the resin is applied in an amount largeenough to overflow from outer peripheries of the mold modules.
 35. Thedrive unit integrated rotating electrical machine according to claim 30,characterized in that: the resin is applied in an amount large enough tooverflow from outer peripheries of the mold modules.
 36. The drive unitintegrated rotating electrical machine according to claim 16,characterized in that: a motor part and a drive unit part are combinedsequentially from a speed reducer attachment side so as to form acoaxial integral structure.
 37. The drive unit integrated rotatingelectrical machine according to claim 35, characterized in that: a motorpart and a drive unit part are combined sequentially from a speedreducer attachment side so as to form a coaxial integral structure. 38.The drive unit integrated rotating electrical machine according to claim16, characterized in that: a drive unit part and a motor part arecombined sequentially from a speed reducer attachment side so as to forma coaxial integral structure.
 39. The drive unit integrated rotatingelectrical machine according to claim 35, characterized in that: a driveunit part and a motor part are combined sequentially from a speedreducer attachment side so as to form a coaxial integral structure.